Fastening device for solar panels

ABSTRACT

A fastening device for fastening at least one solar panel to an assembly rail which has a slot bordered by two parallel webs is disclosed. The fastening device includes a locking element with two locking hooks which can be inserted under elastic deformation of at least a part of the locking element into the slot, and which, when the locking element is relaxed, can then reach behind the webs of the assembly rail. The fastening device further includes at least one hold-down element for a solar panel which is connected with the locking element. At least one interlocking element is provided which can be inserted into an interlocked position between the two locking hooks, where the interlocking element prevents the two locking hooks from coming closer to each other.

This application claims the priority of German Patent Document No. DE 10 2012 209 272.2, filed Jun. 1, 2012, the disclosure of which is expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a fastening device for the fastening of at least one solar panel to an assembly rail which has a slot bordered by two parallel webs. A fastening device of this type is equipped with a locking element with two locking hooks which can be inserted into the slot with the elastic deformation of at least a portion of the locking element and which can then grab the webs of the assembly rail from behind with a relaxation of the locking element, and at least one hold-down element for a solar panel which is connected with the locking element.

European Patent Document No. EP 1 767 793 A2 describes fastening devices for solar panels which can be snapped into the slot of a profile rail. An additional snap-in system is described in International Patent Document No. WO 2007/143983 A2.

The object of the invention is a snap-in fastening device which can be used in a particularly wide variety of applications with a particularly high degree of reliability and little effort and expense.

A fastening device of the present invention is characterized in that at least one interlocking element is provided which can be inserted into an interlocked position between the two locking hooks, in which the interlocking element prevents the two locking hooks from coming closer to each other.

In a fastening device of the invention, a locking element is provided with two facing locking hooks which can be snapped into the slot of the assembly rail. For this purpose, the locking hooks are sized and arranged so that when they are inserted into the slot, they are temporarily pushed together with the elastic deformation of the locking element, in particular by the manual pushing together of the locking elements and/or of the webs of the assembly rail which exert pressure against the locking hooks. As soon as the locking lugs of the locking hooks have traveled past the webs into the interior of the rail, the locking element can relax once again and the elastic deformation can be reduced again, at least partly. The locking hooks are thereby moved apart again until they reach around behind the webs of the assembly rail and optionally are also in contact with the webs. Because the locking hooks are designed in a barb-like fashion, the locking element in this snapped-in position is secured in a form-fitting manner to the webs of the assembly rail to prevent them from falling or being pulled out in the direction at a right angle to the longitudinal extension of the rail and/or at a right angle to the longitudinal extension of the slot.

A basic teaching of the invention can be seen in an interlocking element which, after the locking hooks have been snapped into the slot of the assembly rail, can be brought into an interlocked position between the two locking hooks. In this interlocked position the interlocking element acts as an obstacle to the two locking hooks being brought any closer to each other or can completely prevent them from coming closer to each other, so that it at least makes it more difficult for them to come closer to each other. However, because it is necessary for the two locking hooks to come close together to remove the locking hooks from the slot again, the interlocking element in the interlocked position on one hand provides protection against an undesirable removal of the locking element from the assembly rail. On the other hand the interlocking element can also be designed so that it is oversized, i.e., wider than the gap between the locking hooks, so that the interlocking element in the interlocked position pushes the two locking hooks apart and presses them against the two webs of the assembly rail. In this case the interlocking element can increase the friction of the locking hooks against the webs of the assembly rail and thereby protect the locking element against a displacement along the slot in the assembly rail.

In particular, it thereby becomes possible to achieve a pre-assembled state in which, although the locking element is snapped into the slot, the locking element, however, can move relatively easily along the slot on account of a clearance between the locking hooks and the webs of the assembly rail. Only when the interlocking element is brought into the interlocked position are the locking hooks pressed against the webs and thereby secured to prevent a longitudinal displacement.

It is particularly preferable if a support plate is provided, preferably for at least indirect support and in particular for direct support on the assembly rail, and if the interlocking element is located on the support plate. By integration into a plate of this type, the interlocking element can be positioned particularly easily and securely by the assembler.

It is also advantageous if the support plate has at least one recess, in particular a notch or a hole, which surrounds the locking element, in particular when the interlocking element is in the interlocked position. This measure can further increase reliability. That is because the walls of the recess can form a stop which can restrict a movement of the support plate relative to the locking element and thus a moment of the interlocking element relative to the locking hooks, and can consequently prevent the interlocking element from accidentally falling out or being pulled out of the interlocked position. A notch, as the term is used here, means in particular a recess which is open toward the edge of the plate, while a hole can mean a recess which has a closed circular wall and/or is surrounded in a circular manner by the support plate. The hole can advantageously have a polygonal cross-section, in particular a rectangular cross-section and advantageously a square cross-section, which can simplify the positioning. The locking element can also be introduced into the recess of the support plate even before the insertion of the locking element into the assembly rail, as a result of which, for example, it can be made captive.

It is particularly advantageous if the interlocking element projects into the recess. This measure results in a particularly compact and reliable construction.

An additional advantageous configuration is one in which the interlocking element, in the interlocked position, projects between the two webs of the assembly rail. In this position the interlocking element can secure the locking hooks particularly effectively and can optionally press against the webs. In particular under these conditions it can be advantageous if the support plate has a support plane for at least the indirect contact, and preferably direct contact, against the assembly rail, in particular against the webs of the assembly rail, and if the interlocking element projects from the support plane. The interlocking element preferably runs at and up to an obtuse angle to the support plane and/or projects at an obtuse angle from the support plate, which can, among other things, facilitate insertion. The angle is preferably between 170° and 110°.

It is further advantageous if the support plate has two interlocking elements which project from the support plate on opposite sides of the support plate. This measure can further increase reliability, because the support plate can be installed in two orientations with no loss of functionality. In other words, it does not matter whether the assembler puts the plate in contact with the assembly rail by means of its upper side or by means of its lower side. In particular, the support plate can be axially symmetrical, which can further improve reliability, whereby the axial symmetry is preferred with reference to an axis of symmetry which runs parallel to the support plane and/or at a right angle to the longitudinal direction of the rail.

In another development, the interlocking element is oversized, so that when it is inserted into the interlocked position, it presses the locking hooks apart. In this case, the interlocking element can also advantageously be used to secure the locking element against displacement in the longitudinal direction of the slot, because the interlocking element, on account of its being oversized, can press the locking hooks laterally outward against the webs of the assembly rail.

It is also expedient that the interlocking element has two webs, between which a recess is formed. With this measure, the spring action of the interlocking elements can be adjusted and thus reliability can be further improved.

The locking element is preferably in the shape of a U, in particular in mirror symmetry. When it is in the shape of a U, the locking element has two side legs and one center leg which connects the side legs. The two side legs are advantageously formed by the locking hooks.

The hold-down element can preferably be fastened to the locking element by a screw. The hold-down element advantageously has a pass-through opening through which the screw is inserted. In particular, the screw can be screwed to the locking element, preferably by the middle leg of the locking element.

The invention also relates to a support construction for solar panels with an assembly rail which has a slot which is bordered by two preferably parallel webs, and a fastening device of the invention, advantageously in a configuration in which the locking hooks of the fastening device reach behind the two webs of the assembly rail, in which the locking hooks are therefore snapped in place, and particularly preferably in a configuration in which the interlocking element is inserted into the interlocked position between the two locking hooks and prevents the two locking hooks from coming closer together.

As a result, the advantages described in relation with the fastening device can be achieved in a support construction.

In one preferred development, the interlocking element presses the two locking hooks against the webs of the assembly rail, when it is inserted into the interlocked position, and/or the two locking hooks have some clearance with respect to the webs when the interlocking element is outside the interlocked position. In this configuration, a pre-assembly status can be achieved, as long as the interlocking element is still outside the interlocked position. That is because, in that case, there is a clearance between the snapped-in locking hooks and the webs, so that in the pre-assembly state it at least becomes more difficult for the snapped-in locking element to fall out of the slot, although in this state the locking element can still be pushed essentially freely lengthwise in the slot. Only when the interlocking element is moved into the interlocked position is an interlocked state achieved in which the interlocking element presses the locking hooks laterally against the webs, and in which the locking hooks are therefore secured against the webs positively or non-positively to prevent movement in the longitudinal direction of the slot.

In the pre-assembly state, the interlocking element can be located in particular in a head area of the locking element, in which the two locking hooks are at a comparatively large distance from each other. From here, the interlocking element, which is already inside the locking element, can be moved in a direction at a right angle to the longitudinal extension of the rail and/or at a right angle to the longitudinal extension of the slot, toward the rail into the interlocked position.

It is further preferable if the support plate projects beyond the assembly rail on at least one side, in particular on opposite sides, and advantageously at a right angle to the longitudinal direction of the assembly rail and/or of its slot. In this case, the support plate can also make the contact surface for the solar panels larger. The assembly rails can thereby be manufactured with a particularly small cross-section and therefore economically.

At least one solar panel and preferably two solar panels is or are preferably located between the hold-down element and the support plate. The support plate can in this case also be used in clamping at least one solar panel in position, which can reduce the amount of material required. At least one solar panel is expediently clamped between the hold-down element and the support plate.

The fastening device of the invention is suitable in particular for arrangements in which the assembly rail extends parallel to one edge that faces the fastening device of the solar panel when it is held by the fastening device. Because with such an arrangement only the relatively small transverse dimension extends, if at all, under the solar panels and not the relatively large longitudinal dimension of the assembly rail, the contact surface of the panels on the assembly rail can be made significantly larger with a support plate of the type of the invention.

The invention is explained in greater detail below with reference to advantageous exemplary embodiments which are illustrated schematically in the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a support construction of the invention with a fastening device and an interlocking element in the interlocked position, where only one solar panel is shown for the sake of simplicity;

FIG. 2 illustrates the support construction from FIG. 1 with the interlocking element in the interlocked position, in cross-section;

FIG. 3 illustrates the support construction from FIG. 1 with the interlocking element in the interlocked position in longitudinal section, where one-half of the hold-down element is not shown for the sake of simplicity;

FIG. 4 shows the locking element of the fastening device from FIG. 1 in perspective;

FIG. 5 shows the support plate of the fastening device from FIG. 1 in perspective;

FIG. 6 is a perspective view of the support construction from FIG. 1 during assembly, to illustrate the pre-assembly state;

FIG. 7 is a perspective view of the support construction from FIG. 1 during assembly to illustrate the interlocked condition with the interlocking element in the interlocked position; and

FIG. 8 is a partial view in perspective of the support construction from FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

The Figures show an exemplary embodiment of a support construction of the present invention with a fastening device of the invention. The support construction has an assembly rail 1, in which a slot 10 is made that runs longitudinally in the assembly rail 1 and is bordered by two webs 11 and 12 which run along the assembly rail. The assembly rail can be in particular extruded and/or can have a constant cross-section along its longitudinal extension.

The support construction also has a fastening device 2, with which two neighboring solar panels 4 and 4′ are fastened to the assembly rail 1. The fastening device 2 has a locking element 20 with two neighboring locking hooks 21 and 22, which are connected by a middle leg 23. The locking hooks 21 and 22 and the middle leg 23 thereby form a U-shaped cross-section. At the end of the first locking hook 21 there is a first locking lug 25, which projects outwardly from the first locking hook 21 on the side of the first locking hook 21 which faces away from the second locking hook 22. On the end of the second locking hook 22 there is a second locking lug 26, which projects from the second locking hook 22 on the side of the second locking hook 22 which faces away from the first locking hook 21 (see, for example, FIG. 4). As illustrated in FIG. 2, these barb-like locking lugs 25 and 26 reach behind the webs 11 and 12, respectively, of the assembly rail 1 when the locking element 20 is snapped into the slot 10.

As illustrated in FIG. 4 in particular, the locking hooks 21 and 22 also have a stop web 27 and 28, respectively. The stop webs 27, 28 limit the insertion of the locking element 20 into the slot 10, because they stand up on the webs 11 and 12 of the assembly rail 1. As further illustrated in FIG. 4, the two locking hooks 21 and 22 are at a greater distance from each other in a head area 31 than in a locking area 32, whereby the head area 31 is located between the locking area 32 and the middle leg 23, the locking area 32 is located closer to the locking lugs 25, 26 than the head area 31, and the head area 31 is closer to the middle web 23 than the locking area 32.

The fastening device 2 also has a support plate 40 which is illustrated in particular in FIG. 5. As shown in FIG. 5, the support plate 40 has an approximately rectangular base section, and in particular a square base section. The support plate 40 has, in the center, a recess 49 in the shape of a hole, with a rectangular, in particular square, base section. The locking element 20 can go through this recess 49.

On the support plate 40, a first interlocking element 41 is provided which projects from the edge of the recess 49 into the projection of the recess 49. As illustrated in particular in FIGS. 2 and 3, this interlocking element 41 can be moved into an interlocked position, in which the interlocking element 41 prevents the two locking hooks 21 and 22 from coming closer together, in particular their locking lugs 25 and 26 from coming closer together, and in which the interlocking element 41 presses the two locking hooks 21 and 22 against the webs 11 and 12, respectively, of the slot 10. In the interlocked position, the interlocking element is located in the narrow securing area 32, and for a particularly high application force, preferably between the webs 11 and 12 of the assembly rail 1.

As shown in FIG. 5 in particular, the interlocking element 41 is in the shape of a U with a first web 43 as a stop on one of the locking hooks and a second web 44 as a stop on the other locking hook, where between the two webs 43 and 44 there is a recess 45. As illustrated in FIGS. 2 and 3 in particular, the support plate 40 has a support plane 48 which is in contact on the outside with the assembly rail 1, in particular with its webs 11 and 12, when the interlocking element 41 is in the interlocked position. As illustrated in FIG. 3 in particular, the interlocking element 41 is at an angle from the support surface 40 projecting from this support plane 48.

As illustrated in FIGS. 3 and 5 in particular, the support plate 40, in addition to the first interlocking element 41, also has an additional interlocking element 42 which is located on an opposite side of the recess 49 and which projects from the support plate 40 on a flat side opposite the support plane 48. The second interlocking element 42, analogous to the first interlocking element 41, has two webs and a central recess. The support plate 40 is essentially symmetrical, in particular axially symmetrical, preferably with reference to an axis which runs parallel to the support plane 48.

The fastening device 2 also has a screw 55 and a hold-down element 50, whereby the screw 55 runs through the hold-down element 50 and the head of the screw 55 secures the hold-down element 50 on the screw 55. The screw 55 is screwed into the locking element 20, in particular into the middle leg 23 of the locking element 20. The screw 55 is preferably free to rotate in the hold-down element 50.

The installation of the fastening device 2 on the assembly rail 1 is illustrated in FIGS. 6 and 7. First the locking element 20 is introduced into the support plate 40 and the locking element 20, together with the support plate 40 as illustrated in FIG. 6, is snapped into the slot 10 of the assembly rail 1. The support plate 40 is thereby still in a pre-assembly position in which the two interlocking elements 41 and 42 are in the head region 31, where the two locking hooks 21 and 22 are at a relatively large distance from each other. Thus the locking hooks 21 and 22 in the pre-assembly position are still not being acted on by the interlocking elements 41 and 42. Because the locking hooks 21 and 22 are designed so that there is a certain clearance between them and the webs 11 and 12, the assembler can at this point in the assembly process still move the locking element 20 relatively freely along the assembly rail 1.

As soon as the locking element 20 is in the desired final position, the assembler pushes the support plate 40 downward onto the assembly rail 1 into the position illustrated in FIG. 7. In this interlocked position the interlocking element 41 is brought into its interlocked position in the securing area 32 as illustrated in FIG. 2. In this position, the locking hooks 21 and 22 are pressed by the interlocking element 41 against the webs 11 and 12, so that the locking element 20 is secured against an unintentional or accidental displacement along the assembly rail 1. If it is still necessary to displace the locking element 20, the assembler may lift the support plate 40 back into the pre-assembly position illustrated in FIG. 6.

When the locking element 20 is in the correct position on the assembly rail 1, the solar panels 4 and 4′, which can in particular be photovoltaic panels, are placed on the support plate 40, as illustrated in FIGS. 1 and 2. Then the hold-down element 50 is fastened to the locking element 20 with the screw 55, and by tightening the screw 55 the solar panels 4 and 4′ are clamped between the hold-down element 50 on one side and the assembly rail 1 with the support plate 40 on the other side, and are thereby fastened to the assembly rail 1. Because the solar panels 4 and 4′ are now pressing against the support plate 40, the support plate 40 can no longer return to the pre-assembly position illustrated in FIG. 6 without the application of an external force; in other words, there is a self-securing mechanism.

Because the support plate 40, as shown particularly clearly in FIG. 2, projects in the transverse direction beyond the assembly rail 1, the contact surface available for the solar panels 4 and 4′ is not determined by the width of the rail, and the assembly rail 1 can be made correspondingly narrow and economical. The locking element 20 also acts as a spacer for the neighboring solar panels 4 and 4′, which limits the amount by which the neighboring solar panels 4 and 4′ on the support plate 40 can approach each other, so that the hold-down element 50 can be installed from above in the areas between the two solar panels 4 and 4′.

Because the support plate 40 has two interlocking elements 41 and 42 which are located on opposite sides of the support plate 40 and because the support plate 40 is preferably axially symmetrical, the support plate has no pronounced top or bottom side, and the assembler can consequently not install the support plate 40 upside-down.

The interlocking elements 41 and 42 are deliberately slightly weakened on account of their shape, although preferably not necessarily on account of their recesses 45. Therefore the interlocking elements 41 and 42 can be bent slightly when the combined tolerances of the locking element 20, the slot 10 and the support plate 40 narrow the gap between the locking hooks 21 and 22 in the securing area 32. At the end of the securing area 32 which faces the head area 31, the distance between the locking hooks 21 and 22 can decrease as the distance from the head area 31 increases (e.g., from 6.4 mm to 6 mm in FIG. 8), so that there is a secure interlock even in the presence of manufacturing tolerances.

The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

What is claimed is:
 1. A fastening device for fastening a solar panel to an assembly rail that has a slot bordered by two parallel webs, comprising: a locking element with two locking hooks which are introducible under elastic deformation of at least one part of the locking element into the slot and which are reachable behind the two parallel webs when the locking element relaxes; a hold-down element which is connectable to the locking element; and an interlocking element, wherein the interlocking element is insertable into an interlocked position between the two locking hooks such that the interlocking element prevents the two locking hooks from coming closer to each other.
 2. The fastening device according to claim 1, wherein the interlocking element is disposed on a support plate and wherein the support plate is supportable on the assembly rail.
 3. The fastening device according to claim 2, wherein the support plate has a recess which, in an operative configuration, surrounds the locking element.
 4. The fastening device according to claim 3, wherein the interlocking element projects into the recess.
 5. The fastening device according to claim 2, wherein the support plate has a support plane for support on the assembly rail and wherein the interlocking element projects from the support plane.
 6. The fastening device according to claim 1, further comprising a second interlocking element and a support plate, wherein the support plate is axially symmetrical and wherein the interlocking element and the second interlocking element project on opposite sides of the support plate from the support plate.
 7. The fastening device according to claim 1, wherein the interlocking element is sized such that when it is pushed into the interlocked position, the interlocking element pushes the two locking hooks apart.
 8. The fastening device according to claim 1, wherein the interlocking element has two webs which define a recess.
 9. The fastening device according to claim 1, wherein the locking element has a U-shape and wherein the hold-down element is connectable to the locking element by a screw.
 10. A support construction for a solar panel, comprising: an assembly rail that has a slot bordered by two parallel webs; and a fastening device according to claim 1; wherein the two locking hooks of the locking element reach behind the two webs of the assembly rail.
 11. The support construction according to claim 10, wherein the interlocking element presses the two locking hooks against the two parallel webs of the assembly rail when inserted into the interlocked position and wherein the two locking hooks have a clearance with the two parallel webs when the interlocking element is not in the interlocked position.
 12. The support construction according to claim 10, wherein the interlocking element is disposed on a support plate and the support plate projects beyond the assembly rail on opposite sides.
 13. The support construction according to claim 12 in combination with a solar panel and wherein the solar panel is disposed between the hold-down element and the support plate.
 14. The support construction according to claim 13 wherein the assembly rail extends parallel to an edge of the solar panel facing the fastening device.
 15. A fastening device for fastening a solar panel to an assembly rail, comprising: a locking element with two locking hooks, wherein the two locking hooks are elastically deformable; a hold-down element, wherein the hold-down element is connectable to the locking element; and an interlocking element, wherein, in an operative configuration, the interlocking element is disposed between the two locking hooks.
 16. The fastening device according to claim 15, wherein the interlocking element is disposed on a support plate.
 17. The fastening device according to claim 16, wherein the support plate has a recess and wherein, in the operative configuration, the locking element is disposed through the recess.
 18. The fastening device according to claim 15, wherein the two locking hooks extend from a middle leg of the locking element and wherein the two locking hooks are elastically deformable with respect to the middle leg.
 19. The fastening device according to claim 15 in combination with an assembly rail, wherein the two locking hooks, in the operative configuration, are locked within a slot of the assembly rail.
 20. The fastening device according to claim 19 in combination with a solar panel, wherein the solar panel, in the operative configuration, is disposed between the hold-down element and the assembly rail. 